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Console.ReadKey Method

Obtains the next character or function key pressed by the user. The pressed key is displayed in the console window.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)
[HostProtectionAttribute(SecurityAction.LinkDemand, UI = true)]
public static ConsoleKeyInfo ReadKey()

Return Value

Type: System.ConsoleKeyInfo
A ConsoleKeyInfo object that describes the ConsoleKey constant and Unicode character, if any, that correspond to the pressed console key. The ConsoleKeyInfo object also describes, in a bitwise combination of ConsoleModifiers values, whether one or more SHIFT, ALT, or CTRL modifier keys was pressed simultaneously with the console key.
ExceptionCondition
InvalidOperationException

The In property is redirected from some stream other than the console.

The ReadKey method waits, that is, blocks on the thread issuing the ReadKey method, until a character or function key is pressed. A character or function key can be pressed in combination with one or more ALT, CTRL, or SHIFT modifier keys. However, pressing a modifier key by itself will not cause the ReadKey method to return.

Depending on your application, you might want to use the ReadKey method in conjunction with the KeyAvailable property.

The ReadKey method reads from the keyboard even if the standard input is redirected to a file with the SetIn method.

NoteNote

The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: UI. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

The following example demonstrates the parameterless ReadKey method.


using System;

class Example 
{
   public static void Main() 
   {
      ConsoleKeyInfo cki;
      // Prevent example from ending if CTL+C is pressed.
      Console.TreatControlCAsInput = true;

      Console.WriteLine("Press any combination of CTL, ALT, and SHIFT, and a console key.");
      Console.WriteLine("Press the Escape (Esc) key to quit: \n");
      do 
      {
         cki = Console.ReadKey();
         Console.Write(" --- You pressed ");
         if((cki.Modifiers & ConsoleModifiers.Alt) != 0) Console.Write("ALT+");
         if((cki.Modifiers & ConsoleModifiers.Shift) != 0) Console.Write("SHIFT+");
         if((cki.Modifiers & ConsoleModifiers.Control) != 0) Console.Write("CTL+");
         Console.WriteLine(cki.Key.ToString());
       } while (cki.Key != ConsoleKey.Escape);
    }
}
// This example displays output similar to the following:
//       Press any combination of CTL, ALT, and SHIFT, and a console key.
//       Press the Escape (Esc) key to quit:
//       
//       a --- You pressed A 
//       k --- You pressed ALT+K 
//       ► --- You pressed CTL+P 
//         --- You pressed RightArrow 
//       R --- You pressed SHIFT+R 
//                --- You pressed CTL+I 
//       j --- You pressed ALT+J 
//       O --- You pressed SHIFT+O 
//       § --- You pressed CTL+U 


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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